Hardware Methods for Onboard Control of Fluidically Actuated Soft Robots

Soft robots provide significant advantages over their rigid counterparts. These compliant, dexterous devices can navigate delicate environments with ease without damage to themselves or their surroundings. With many degrees of freedom, a single soft robotic actuator can achieve configurations that would be very challenging to obtain when using a rigid linkage. Because of these qualities, soft robots are well suited for human interaction. While there are many types of soft robot actuation, the most common type is fluidic actuation, where a pressurized fluid is used to inflate the device, causing bending or some other deformation. This affords advantages with regards to size, ease of manufacturing, and power delivery, but can pose issues when it comes to controlling the robot. Any device capable of complex tasks such as navigation requires multiple actuators working together. Traditionally, these have each required their own mechanism outside of the robot to control the pressure within. Beyond the limitations on autonomy that such a benchtop controller induces, the tether of tubing connecting the robot to its controller can increase stiffness, reduce reaction speed, and hinder miniaturization. Recently, a variety of techniques have been used to integrate control hardware into soft fluidic robots. These methods are varied and draw from disciplines including microfluidics, digital logic, and material science. In this review paper, we discuss the state of the art of onboard control hardware for soft fluidic robots with an emphasis on novel valve designs, including an overview of the prevailing techniques, how they differ, and how they compare to each other. We also define metrics to guide our comparison and discussion. Since the uses for soft robots can be so varied, the control system for one robot may very likely be inappropriate for use in another. We therefore wish to give an appreciation for the breadth of options available to soft roboticists today.

General and Gambling-Specific Types of Control: Extending Mental Health Theory and Concepts to Problem Gambling

Rationale: A key factor in our understanding of problem gambling is control: over gambling outcomes (illusion of control) and behaviours (gambling self-efficacy). Research in the gambling field rarely looks beyond these gambling-specific types of control to more general types when identifying predictors of gambling problems. This work begins to integrate control concepts from the mental health and problem gambling fields by examining the importance of a more general type of control from the Stress Process Model: sense of control over life events. Methods: Closed-ended questionnaire and open-ended interview responses from 30 frequent (weekly or more) gamblers were used to examine whether general and gambling-specific types of control are linked as predicted in a conceptual model of control. Results: For some people, beliefs about one type of control are extended to inform beliefs about another type of control. In many cases, understandings of outcomes in life inform beliefs about controlling gambling outcomes and behaviours. Conclusions: Different types of control work together, and general understandings can translate into gambling-specific beliefs. Future work is needed to confirm and specify these relationships and clarify their importance to understanding the development of gambling problems.

Pregnancy-related plasticity of gastric vagal afferent signals in mice

Gastric vagal afferents (GVAs) sense food related mechanical stimuli and signal to the central nervous system, to integrate control of meal termination. Pregnancy is characterized by increased maternal food intake, which is essential for normal fetal growth and to maximize progeny survival and health. However, it is unknown whether GVA function is altered during pregnancy to promote food intake. This study aimed to determine the mechanosensitivity of GVAs and food intake during early-, mid-, and late- stages of pregnancy in mice. Pregnant mice consumed more food compared to non-pregnant mice, notably in the light phase during mid- and late pregnancy. The increased food intake was predominantly due to light phase increases in meal size across all stages of pregnancy. The sensitivity of GVA tension receptors to gastric distension was significantly attenuated in mid- and late pregnancy, while the sensitivity of GVA mucosal receptors to mucosal stroking was unchanged during pregnancy. To determine whether pregnancy associated hormonal changes drive these adaptations, the effects of estradiol, progesterone, prolactin and growth hormone, on GVA tension receptor mechanosensitivity were determined in non-pregnant female mice. The sensitivity of GVA tension receptors to gastric distension was augmented by estradiol, attenuated by growth hormone and unaffected by progesterone or prolactin. Together, the data indicate that the sensitivity of GVA tension receptors to tension is reduced during pregnancy, which may attenuate the perception of gastric fullness and explain increased food intake. Further, these adaptations may be driven by increases in maternal circulating growth hormone levels during pregnancy.

Modeling of Flexible Bodies for the Study of Control in the Simulink Environment

When studying complex mechatronic systems, it is useful to build models able to simulate both the dynamics of the phenomenon and the control system applied. Typically, the bodies involved are modeled as rigid bodies. In this work, a technique for modeling flexible bodies in Simulink environment is presented. Simulink is a powerful instrument where it is quite easy to integrate control algorithms with complex systems. The solution developed is presented and applied to a machining center. Modern machining centers ensure a level of accuracy that traditional manual machines cannot reach. Simulations of the working process considering vibrations are needed to obtain high precision machining. These simulations aim to determine the error in the position of the tool and to help designers in finding the optimal solution in terms of machining velocity and precision. This work is focused on the carriage of a machine tool moving along horizontal guides, typically named Z-axis. The axis is actuated and borne by a linear motor; therefore, movable constraints must be modeled. A finite-element (FE) model of the carriage was reduced with a Craig-Bampton reduction to provide the mass and stiffness matrices for an in-house Matlab simulation code. The rigid constraints of the carriage were implemented in the model as moving stiffnesses, and their value was set to obtain continuity of the constraints in the discrete model. In the end, a map of different vibrational configurations is proposed to visualize the possible errors that a machining process can generate.

Sistem Penyeleksi Warna Dan Berat Barang Menggunakan Pergerakan Lengan Robot Empat DOF (Degree Of Freedom)

The use of robot arm in the system of colour and weight box selection has been done to integrate control system of robot arm moving with colour sensor TCS3200 and weight sensor load cell. The research was conducted by analyzing efficiency and accuracy system of robot arm moving to select colour and weight goods like box. The robot arm moving work suitable instruction of colour and weight sensor reading. At the most important from this system is how to accuracy of colour and weight sensor to detect colour ang weight and accuracy of robot arm moving system can positioning degree moving to take colour with different weight box suitable the place. The result of the analysis proved that robot arm moving had inregrated with colour and weight sensor efficient and effective to do this work as colour and weight box selection accurately.

The role of feedforward control in motor planning

In dynamical systems models feedforward is needed to guide planning and to process unknown and unpredictable events. Feedforward could help Theory of Event Coding (TEC) integrate control processes and could model human performance in action planning in a more flexible and powerful way.